What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The aircraft had been in maintenance for two years and approved for return to service on 1/8/2020. The owner taxied out to the runway for a fast taxi test following extensive maintenance. The owner reported rolling over a soft spot in the grass runway causing the tail to bounce up. This caused the short-coupled aircraft to nose-over and flip inverted. The owner was secured in the single seat with a five-point harness and only sustained minor lacerations to his face when the canopy broke. There was no intention of flight, therefore, this is an incident as defined by 49 CFR 830.2 "definitions".
As the FAA filed it
THE AIRCRAFT HAD BEEN IN MAINTENANCE FOR TWO YEARS AND APPROVED FOR RETURN TO SERVICE ON 1/8/2020. THE OWNER TAXIED OUT TO THE RUNWAY FOR A FAST TAXI TEST FOLLOWING EXTENSIVE MAINTENANCE. THE OWNER REPORTED ROLLING OVER A SOFT SPOT IN THE GRASS RUNWAY CAUSING THE TAIL TO BOUNCE UP. THIS CAUSED THE SHORT-COUPLED AIRCRAFT TO NOSE-OVER AND FLIP INVERTED. THE OWNER WAS SECURED IN THE SINGLE SEAT WITH A FIVE-POINT HARNESS AND ONLY SUSTAINED MINOR LACERATIONS TO HIS FACE WHEN THE CANOPY BROKE. THERE WAS NO INTENTION OF FLIGHT, THEREFORE, THIS IS AN INCIDENT AS DEFINED BY 49 CFR 830.2 "DEFINITIONS".